by in2anity » 01 Nov 2017, 1:52 pm
In terms of seating it sounds like you're spot-on with your process. The only thing to add I guess is I'm not sure how important the crimp is shooting 30cal lead through a 308w rifle (like the BLR or a bolt); crimping puts more stress on the brass and reduces its life so you should only do it if necessary. Definitely crimp for the 30/30 though (as you've done).
There's probably not really a need for magnum primers with TB - magnum primers are more for when you think you are not achieving uniform burns (for example a big magnum cartridge with a lot of powder). Or in contrast when you have a reduced load only partially filling the case, where powder positioning can change depending on how you hold the rifle prior to each shot. In your case (the 30/30), examples of appropriate reduced-load powders would be AR2205 or AR2207 - for these powders, it actually helps to tilt the rifle skyward prior to each shot to position the powder back onto the primer. Either that or experiment with case fillers, which is a very divided realm as to whether case fillers are a good idea.
But because TB is such sparse "fluffy" fast burning powder, your burns should be fairly consistent (because the case is pretty much full). In saying that, there's probably no harm in using magnum primers, and for the sake of minimizing variable changes, I'd probably just stick to your magnums for now while you focus on other others (like loads).
In terms of a specific load, levers are notoriously specific/finicky when it comes to load development; a lot more than a bolt gun, very much a case of "each rifle is different". I'm not sure how much use it is, but FWIW my marlin 30/30 seemed to achieve peak TB accuracy at around 8.4 gr of TB.
SHV is your winnie tapped on the side for an aperture sight? Developing loads with only dovetail sights is indeed tricky...
At what point does lack of maintenance become patina?